366 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1924 



flowers are mostly rose or purple, but in some species white, and all 

 are very showy. Some of the species flower almost throughout the 

 year, but the habit of flowering is peculiar. All over a large clump 

 of plants the flowers open, one on each stalk, on a certain morning. 

 They remain open for only a few hours, then close, and fall from 

 the plant unless they have been fertilized. After several days there 

 is another crop of blossoms, but meanwhile not a single flower will 

 have been seen upon the colony. 



Worthy of mention because of their oddity are the species of 

 Ornithocephalus, which are not uncommon in both Panama and 

 Costa Rica (pi. 18). The flowers are minute, greenish yellow, and 

 in form bear some resemblance to a bird's head, hence the generic 

 name. The plant is fan-shaped, the leaves being flat and all in one 

 plane, resembling in this respect iris leaves. This fan-shaped ar- 

 rangement of leaves is found in various other Panama orchids, nota- 

 bly in a diminutive Oncidium that is abundant upon cacao branches 

 at Las Cascadas Plantation. In this the leaves are often not more 

 than half an inch in length, while the flow^ers, of which there is 

 sometimes only one, are frequently much larger than the plant 

 proper. This is unusual among orchids, since ordinarily small plants 

 have the smallest flowers. 



To list all the orchids of Panama or only the more important ones 

 would far exceed the limits of this paper, and would serve no useful 

 purpose, since it would merely furnish a list of uninteresting Latin 

 names. In fact, very few orchids have distinctive English names, 

 and even among gardeners it is the custom to refer to the plants 

 by their generic names, which after all is the only means by which 

 accuracy in plant names may be attained. Photographs give 

 little idea of the modifications exhibited by the flowers, but exami- 

 nation of the plants themselves when in flower is a different matter, 

 for then almost anyone is interested in observing the unbelievable 

 variety presented, a variation in form and coloration not equaled in 

 any other family of plants. 



In spite of the great diversity exhibited by orchid flowers, it must 

 be stated that this results only from the modification of organs which 

 are common to other groups of plants. The flower consists of three 

 sepals and three petals, one of the latter being normally very dif- 

 ferent from the other two and called the lip or labellum. The three 

 stamens, of which one or two are abortive, are united with the pistil 

 to form a column, which also is often specially modified. 



ORCHID COLLECTING IN COSTA RICA 



Really to see orchids one must go to Costa Rica, where they 

 almost fill the role of weeds. After becoming familiar with the 

 profusion of orchids, as to both individuals and species, that exists 



